Please correct the sentences below so they sound natural. If natural, then it's fine.

I really realized the importance of my family when I became a collage student and started living on my own. I don't usually pay careful attention to the fact that I breathe. Likewise, I had not been aware of the importance of my family, because it had been always there. In that sense, my family was like the air I breathe. And I was quite uncomfortable when I separated myself from such an important thing.

(Taka, if you don't mind, I offer an additional change-- in the order of the expressed thoughts.)

I really realized the importance of my family when I became a college student and started living on my own. I had never been very aware of the importance of my family, because it had always been there. In a sense, my family was like the air I breathe, (I don't usually pay careful attention to the fact that I breathe). So I was quite uncomfortable when my family and I were separated.

I really realized the importance of my family when I became a college student and started living on my own. I don't usually pay careful attention to the fact that I breathe. Likewise, I ('wasn't' is probably more natural)had not been aware of the importance of my family, because it had always been there. In that sense, my family was like the air I breathe. And I was quite uncomfortable when I separated myself from such an important thing.

I looked at this on the assumption that it represents spoken and informal English. If you wrote this yourself, I think you are getting a really good feeling for the language.

taka, like clive i think that your sentences sound quite natural. however, from an editor's perspective i agree with davkett. while the first passage keeps jumping back and forth between your need for family and air, the second arrangement is more concise and flows a bit easier into the metaphor. also, by removing 'I don't usually pay careful attention to the fact that I breathe' you then allow readers the independence to grasp at the metaphor on their own. but beware -- this second arrangment shifts the focus of the paragraph almost entirely onto your lack of family whereas the first version seems to equally explore your need for family and air. gosh, now i'm rambling...sorry!

CliveI looked at this on the assumption that it represents spoken and informal English.

Your assumption is right. Actually, it's a translation of the sentences originally written in Japanese, and the original is quite colloquial.

CliveIf you wrote this yourself, I think you are getting a really good feeling for the language.

Thank you for the compliment, Clive! It makes me feel good!

------ davkett, and The17pointscale,

As I said above, it's a translation, and I tried to translate as faithfully as possible. It doesn't seem like the original writer was conscious of coherence, like the topic sentence, body and conclusion.

Thank you for the advice, anyway (but I think your advice should go to the original author ).